Yuo could think outside the box... create a temp table with the values for your IN clause, and then do a join.
For example, if you want:
where col1 IN (2,5,7)
create a one column table that contains three records with these values, and then say:
where col1 = #tmp.Col
Depending on your particular case, you can also code a "select distinct...into" to get ALL possible values if you really want to leave off the IN clause.
Of course, that may not always be practicable.
jef